In the field of color photographs widely popularized today, particularly, color prints, the production is carried out in a centralized processing system at a production base called a color lab. where a high speed printer for mass production or a large-sized processing equipment is installed or in a distributed processing system using a small-sized printer processor called a mini lab. installed in a shop.
The techniques in either of these print production systems have been recently developed while giving priority to the viewpoint that "how rapidly prints can be produced".
In particular, as a result of practical utilization of a light-sensitive material for printing using a high silver chloride emulsion and an image formation method using the material, the processing steps conducted on the market predominantly take 4 minutes or less for the time from the entering of a color printing paper into a processing solution after exposure to the completion of development followed by drying, namely, for a so-called dry-to-dry time.
However, the demand for more and more rapid processing goes ahead of the advancement in such a technique and is highly intensified. One of the reasons therefor is the appearance of various systems able to form a full color image. More specifically, in addition to a so-called conventional silver salt photographic system for obtaining a color image comprising exposing and then developing a photographic light-sensitive material using such silver halide as described above, a great number of image formation systems such as a heat development system or a heat-sensitive transfer system have been recently proposed. These systems are characterized in that the wet development which is a bottleneck in the application of silver salt photographic system is not required. Accordingly, in order to achieve further development of the silver salt photographic system to cope with these systems, the realization of more rapid and simple development processing is an important theme.
On the other hand, when considered the above-described concurrence, in parallel to the improvement in simplicity and rapidity of processing, it is also of course important to maintain and improve fastness of a dye image which is an advantage of the conventional silver salt photographic system without losing even under such processing conditions.
A light-sensitive material for color printing (color printing paper) usually comprises light-sensitive emulsion layers sensitive to blue, green and red lights lying in three different wavelength regions and each emulsion layer is constructed so that a dye in a complementary relation to the light to which the layer is sensitive, namely, a yellow dye in the blue-sensitive emulsion layer, a magenta dye in the green-sensitive emulsion and a cyan dye in the red-sensitive emulsion layer, can be formed. Each layer contains a combination of a silver halide emulsion as a light-sensitive element spectrally sensitized to a desired wavelength region and a color coupler as a dye-forming agent. The color coupler makes a coupling reaction with an oxidation product of a developing agent formed during development of an exposed silver halide emulsion to form a dye image. Accordingly, a great number of techniques have been proposed on the color coupler so as to improve fastness of a dye image. However, the current techniques have not yet reached a sufficient level to achieve a rapid and at the same time simple development processing.
One of the techniques for realizing a rapid processing is a technique where a high silver chloride emulsion is used to increase the development speed of silver halide to thereby achieve a rapid processing.
From the viewpoints other than this, a large number of techniques have been reported to attain reduction in the development time of a silver halide photographic light-sensitive material.
For example, JP-A-63-38937 (the term "JP-A" as used herein means an "unexamined published Japanese patent application") discloses a technique for controlling the swelled film thickness of a light-sensitive material or a coating amount of gelatin by means of a processing solution.
Also, JP-A-3-109549 discloses a technique for suppressing the alkali consumption in emulsion layers constituting the light-sensitive material to achieve a rapid development.
Further, JP-A-4-443 describes that a dye image having superior fastness and a super high speed processing at a low replenishing rate for the developer can be realized by processing a light-sensitive material containing a high silver chloride silver halide emulsion with a color developer containing a hydroxyalkyl-substituted p-phenylenediamine derivative of a specific structure as a color developing agent.
However, these methods can hardly achieve a rapid processing and at the same time high fastness of a dye image to light or heat. In other words, the light-sensitive material produced according to conventional techniques may be able to be processed rapidly and simply, but the fatness of a dye image obtained, in particular, a magenta dye image, is readily impaired and further, the white background after a long-term storage of processed prints is easily deteriorated, which is a problem.
It is known to improve the fatness of a dye image by bettering a dye-forming coupler used. For example, JP-A-1-302249 presents the use of a magenta coupler having a branched alkyl group as a substituent in the pyrazolotriazole ring to improve the light or heat fastness of the resulting magenta dye image, however, the effect is not sufficient when applied a rapid processing requiring a short processing time and using the above-described high silver chloride emulsion and the technique is not suitable for a further rapid processing. Also, the magenta coupler described in the patent publication above is broad in color hue of the resulting dye and has a problem to be solved in view of reproduction of a highly pure color.
EP 0571959 discloses that the use of a 1H-pyrazolo-[1,5-b][1,2,4]triazole magenta coupler having, in the pyrazolotriazole ring, a tertiary alkyl group at the 6-position and an amido group-substituted phenyl group at the 2-position brings about a small change in color density even under fluctuation in the processing solution compositions or a reduction in regression of a latent image and also that the color image formed has superior fastness to light or heat.
However, a still further improvement is desired in view of color forming property or preservability of a white background of prints in the application of a rapid processing, in particular, a rapid processing requiring the total processing time from color development to water washing or stabilization of 2 minutes or shorter.